KAK 5/8-24 Slimline Flash Can 3.25in AR15-UP-261. 200 Dia 3.250 Long 6061 Aluminum Black Hard Anodized Finish 3.19 Oz. 3/4 Wrench Flats This Muzzle Device Will Fit Inside Utg Pro Aero Cop And Other Rails That Will Not Clear The Original Larger Version...